1. Field of the Invention
The present invention relates to a subject associating device for associating the subject of a sentence inputted and a word association device for associating the subject of the inputted sentence to associate a word appropriate to the associated subject.
2. Description of the Prior Art
It is expected that in the future, an automatic telephone translation system will be capable of translating speech from the calling party into another language before the call is received by the receiving party. The automatic telephone translation system, achieves an acceptable level of recognition performance by associating a subject on the basis of voice speech and a recognition vocabulary of about 3,000 words used in the context of the associated subject.
On the other hand, as discussed above, the following method has been suggested in an article "Association-Based Parser for Speech Understanding Sytems", Denshi Jouhou Tsuushin Gakkai Ronbunshuu (Collection of Treatises of the Society of Electronic Information and Communication), Vol. J71-D No. 5, pp. 782-789, as a method of associating a subject from imput speech. According to this association-based parser, a recognition is made of a speech of a statement descriptive of a scene expressed with the use of a vocabulary of about 1,000 words, spoken phrase to phrase, and association of a subject is made with the use of a semantic and contextural restriction which may be a subject and situation network, so that out of plural recognized phrase candidates a proper phrase candidate can be selected by selecting a word appropriate to the associated subject.
However, the following problems occur when the semantic and contextural restriction analogous to the above discussed subject and situation network is to be configured Namely, as shown in FIG. 2, a subject shifts slowly as compared with a situation. However, there is no objective difference between the subject and the situation and the definition of the subject and the situation varies from person to person. By way of example, if the following paragraph is presented to six panelists (Associators A, B, C, D, E and F), each of them will associate the following subject and situation.